cavsvideodec.c 2.3 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768
  1. /*
  2. * RAW Chinese AVS video demuxer
  3. * Copyright (c) 2009 Stefan Gehrer <stefan.gehrer@gmx.de>
  4. *
  5. * This file is part of FFmpeg.
  6. *
  7. * FFmpeg is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU Lesser General Public
  9. * License as published by the Free Software Foundation; either
  10. * version 2.1 of the License, or (at your option) any later version.
  11. *
  12. * FFmpeg is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15. * Lesser General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU Lesser General Public
  18. * License along with FFmpeg; if not, write to the Free Software
  19. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20. */
  21. #include "avformat.h"
  22. #include "rawdec.h"
  23. #define CAVS_SEQ_START_CODE 0x000001b0
  24. #define CAVS_PIC_I_START_CODE 0x000001b3
  25. #define CAVS_UNDEF_START_CODE 0x000001b4
  26. #define CAVS_PIC_PB_START_CODE 0x000001b6
  27. #define CAVS_VIDEO_EDIT_CODE 0x000001b7
  28. #define CAVS_PROFILE_JIZHUN 0x20
  29. static int cavsvideo_probe(AVProbeData *p)
  30. {
  31. uint32_t code= -1;
  32. int pic=0, seq=0, slice_pos = 0;
  33. int i;
  34. for(i=0; i<p->buf_size; i++){
  35. code = (code<<8) + p->buf[i];
  36. if ((code & 0xffffff00) == 0x100) {
  37. if(code < CAVS_SEQ_START_CODE) {
  38. /* slices have to be consecutive */
  39. if(code < slice_pos)
  40. return 0;
  41. slice_pos = code;
  42. } else {
  43. slice_pos = 0;
  44. }
  45. if (code == CAVS_SEQ_START_CODE) {
  46. seq++;
  47. /* check for the only currently supported profile */
  48. if(p->buf[i+1] != CAVS_PROFILE_JIZHUN)
  49. return 0;
  50. } else if ((code == CAVS_PIC_I_START_CODE) ||
  51. (code == CAVS_PIC_PB_START_CODE)) {
  52. pic++;
  53. } else if ((code == CAVS_UNDEF_START_CODE) ||
  54. (code > CAVS_VIDEO_EDIT_CODE)) {
  55. return 0;
  56. }
  57. }
  58. }
  59. if(seq && seq*9<=pic*10)
  60. return AVPROBE_SCORE_MAX/2;
  61. return 0;
  62. }
  63. FF_DEF_RAWVIDEO_DEMUXER(cavsvideo, "raw Chinese AVS video", cavsvideo_probe, NULL, CODEC_ID_CAVS)